One of the challenges of characterizing any random orientation of 1-D conductors or semiconductors is measuring the anisotropy in alignment in a specified direction. One commonly used approach to determine such alignment of 1-D conductors or semiconductors has been to use physical characterization techniques, such as, scanning electron microscopy (SEM) or atomic force microscopy (AFM) to determine alignment. One of the drawbacks of such an approach, using SEM or AFM, is that it is an extremely slow and tedious process due to manual nature of image acquisition and image processing to count the number of 1-D semiconductors or conductors along given orientation. Such an approach can also lead to inaccuracies in measurement.
Another approach to determine alignment of 1-D conductors or semiconductors has involved the use of Raman spectroscopy. This approach uses the intensity of a characteristic radial breathing mode (RBM) for a given orientation of a substrate with respect to the polarization of the exciting beam of light. The Raman spectroscopy approach is also extremely slow, especially with 1-D conductors, because it requires either rotating the substrate or polarization of exciting light to acquire RBM intensity along a given direction. Low intensity of light scattered from 1-D conductors, which inherently have low capture-cross section, will force the user to use longer integration times which can also slow down this approach significantly.